These pages are intended to provide an overview of water reuse
and other alternative water supplies associated with
sustainable water management. Each of the seven sub-sections
focuses on a different topic and contains background information,
illustrated case studies and references. Since this is a web-based
resource most of the references are to other internet sources. The
case studies cover the full breadth of water reuse applications,
from the reuse of municipal wastewater for industry and irrigation
of a championship golf course to an urban greywater recycling
scheme for blocks of flats.
Click on the sub-section links at the bottom of this
page to access the different topics
What is water reuse?
Water reuse describes the process
whereby wastewater treated to an appropriate standard, is reused
for a variety of beneficial purposes. The treated water ready to be
reused is termed recycled or reclaimed water.
There are over 3300 reuse projects internationally with
approximately 700 in Europe. The growth in the flow rate capacity
each year is 25 to 60% in the countries that recognise the benefits
of reuse. Click on the diagram to see an enlarged version of
the reuse water cycle .
Why reuse water?
Water is an increasingly scarce resource for much of the World's
population. Global warming, an increasing world population and
generally increasing incomes mean the demand for water is likely to
rise further. If current trends continue, we will use 40% more
water by 2024 than we do now. In industrialised countries much
of the water used for non-potable purposes such as industrial
applications, toilet flushing and irrigation, is unnecessarily
treated to potable-water standard. We have to carefully treat
wastewater to protect water resources and ensure water is available
for abstraction. We need to take care not to
over-abstract water from rivers and aquifers but instead
to reduce abstraction to within sustainable limits.
Benefits of water reuse include:
- Increasing water resource availability
- Making scarce potable water previously used for non potable
applications available for drinking
- Reduced consumption of expensively treated potable water
supplies (cost saving where there is water metering)
- Reduced effluent flow loads to sewers
- Reduced nutrient discharge to water bodies
- Flood prevention potential (storage)
- A less drought sensitive water resource
- Enhanced recreation and tourism opportunities and biodiversity
benefits through the restoration/creation of wetlands
Is water reuse the only option?
Sustainable water management involves demand-side measures (such
as installing water-efficient appliances, bathroom fittings and
being 'waterwise') as well as the supply-side measures which are
discussed in this section (water reuse other and other alternative
water supplies like appropriately treated rainwater and desalinised
sea water). Usually it is more effective to reduce demand
for water at point of use before supply-side measures are